Plasma arc torches are widely used for high temperature processing (e.g., heating, cutting, gouging and marking) of materials. A plasma arc torch generally includes a torch head, an electrode mounted within the torch head, an emissive insert disposed within a bore of the electrode, a nozzle with a central exit orifice mounted within the torch head, a shield, electrical connections, and passages for cooling, passages for arc control fluids (e.g., plasma gas). A swirl ring can be used to control fluid flow patterns in the plasma chamber formed between the electrode and the nozzle. For liquid cooled plasma arc torches, a coolant tube can be installed in each torch to deliver a liquid coolant to various consumables in the torch tip to prevent overheating. In some torches, a retaining cap is used to maintain the nozzle and/or swirl ring in the plasma arc torch. In operation, the torch produces a plasma arc, which is a constricted jet of an ionized gas with high temperature and sufficient momentum to assist with removal of molten metal. Gases used in the torch can be non-reactive (e.g., argon or nitrogen), or reactive (e.g., oxygen or air).
Existing liquid cooled plasma arc torches require the use of different coolant tubes to accommodate electrodes of different sizes for difference cutting processes. For example, an 80-amp cutting process may require installation of a longer electrode than a 300-amp cutting process, which necessitates the use of different coolant tubes to accommodate the electrodes of different lengths. Improvements are thus needed to simplify torch parts and reduce the number of consumable components installed and/or removed relative to a torch body when the cutting process is changed.